1. Field of the Invention
This invention relates generally to sewing machines and more particularly to a sewing machine provided with a threading hook which passes a thread through a needle eye.
2. Description of the Related Art
JP-B-7-71596 discloses a threading apparatus for a sewing machine comprising a threading hook allowed to pass through a needle eye, a threading bar supporting the hook, a rotating member for rotating the hook only when the needle is located at a higher position than a predetermined position, a holding member for holding a needle thread at two positions, a moving mechanism for moving the holding member near the needle eye, and an operating member operated so that the threading bar is moved upward and downward and rotated.
In the above-described threading apparatus, a moving speed of the hook is increased when a user operates the operating member quickly. Depending upon the environment where the sewing machine is installed and a material for the thread, the threading hook cannot sometimes catch the thread even when the moving speed of the hook is slightly higher than an expected speed. Furthermore, although the thread is caused to come close to the needle eye in the above-described threading apparatus, the thread is only tight-stretched before the needle eye. Accordingly, the threading hook cannot sometimes catch the thread when the position of the thread is changed depending upon a material or twisting manner of the thread or the like.